Power supply and phase responsive apparatus

ABSTRACT

A power supply and phase responsive apparatus connected by two wires to a remote electric clock thermostat for supplying power to the clock motor and connecting a temperature responsive switch apparatus in the thermostat over the same two wires to a relay associated with the phase responsive apparatus for controlling temperature conditioning apparatus furnishing heated air from a furnace to the space containing the clock thermostat. The phase responsive apparatus responding to the phase of the voltage and current supplied to the clock thermostat whereby normally with only the clock operating, the current lags the voltage, but upon the temperature responsive switch apparatus closing an additional capacitive circuit, the current is either in phase or leads the voltage to result in the energization of the relay and thus the conditioning apparatus.

United States Patent Pinckaers POWER SUPPLY AND PHASE RESPONSIVE PrimaryExaminerGerald Goldberg APPARATUS Attorney Lamont B. Koontz and Clyde C.Blinn [75] Inventor: Balthasar H. Pinckaers, Edina,

Minn. [57] ABSTRACT A power supply and phase responsive apparatus con-[73] Asslgnee Honeywell Mmneapohs nected by two wires to a remoteelectric clock thermo- [22] Filed: Nov. 9, 1970 stat for supplying powerto the clock motor and connecting a temperature responsive switchapparatus in [21 1 Appl' 88093 the thermostat over the same two wires toa relay asso- Related U.S. Application Data ciated with the phaseresponsive apparatus for control- [62] Division of Ser. No. 856,062,Sept. 8, 1969, Pat. No. "8 lemperame conditioning apparel furnishing3,599,363, heated air from a furnace to the space containing the clockthermostat. The phase responsive apparatus re- 52 U.S. CI. 323/119,323/20, 323/105, Spending to the Phase of the voltage and current 323/3plied to the clock thermostat whereby normally with [51] Int. Cl. GOSf5/00 y clock Operating, the Current lags the g [58] Field of Search323/20, 22 T, 102, but p the temperature responsive Switch apparatus 323105 1 9 127 129 34 35 3 23 4 closing an additional capacitive circuit,the current is either in phase or leads the voltage to result in theener- [56] Refe Ci gization of the relay and thus the conditioningappara- UNITED STATES PATENTS 3,551,799 /1 70 Koppelmann 323/127 8 lllS,2 Drawing Figures 3,614,568 10/1971 Metallistov et al. 323/20 GEAR t CAM7 TRAIN MECHANISM 3 A 22 FURNACE i FAN PATENTED JUN 26 I975 Mm A wo zmiPOWER SUPPLY AND PHASE RESPONSIVE APPARATUS This application is adivision of application Ser. No. 856,062 filed Sept. 8, 1969 now US.Pat. No. 3,599,868.

BACKGROUND OF THE INVENTION For many years, electric clock thermostatshave been used for controlling temperature conditioning apparatus suchas a furnace in a dwelling. An electric clock thermostat generally has atemperature responsive switch apparatus similar to the conventionalthermostat which is connected to control the furnace. Associated withthe temperature responsive switch apparatus is an electric clock motorwhich is connected to a cam mechanism to selectively adjust the controlpoint of the temperature responsive switch apparatus to select differenttemperatures to be maintained in the space by thermostat. Suchselections are made by the homeowner by setting the clock mechanism toadjust the control point of the thermostat to different levels duringdifferent time periods such as a lower temperature setting during thenighttime. Such electric clock thermostats as shown in the Willis l-I.Gille US. Pat. No. 2,632,797 have for some time required at least threewires to connect the clock thermostat to an associated remote controlapparatus for the furnace.

In a co-pending patent application of Clifford Nelson, et al., now US.Pat. No. 3,620,448, issued Nov. I6, 1971 an electric clock thermostat isdisclosed for use with a two-wire circuit to supply power to the clockmotor and provide a control circuit on the same two wires. When aconventional thermostat is connected to the remote control apparatus forcontrolling the furnace, a two-wire circuit is generally used. Thereplacement of the conventional thermostat can be made with an electricclock thermostat of the Nelson et al application without the need ofadditional wires.

The present invention provides an improved power supply and phaseresponsive apparatus which has as one use the supply of power to anelectric clock thermostat system of the type shown in the divisionalapplication of Balthasar H. Pinckaers now US. Pat. No. 3,599,863 issuedAug. 17, I971.

DESCRIPTION OF THE INVENTION FIG. 1 is a schematic representation of theconnection of an electric clock thermostat to a power supply and phaseresponsive apparatus adapted to control the operation of a furnace.

FIG. 2 is a second embodiment of this specific circuit used in the powersupply and phase responsive apparatus of FIG. 1.

Referring to FIG. 1, an electric clock thermostat or environmentalcondition responsive apparatus is mounted in a space 11 in which thetemperature is to be controlled. Thermostat 10 is connected over acircuit using two wires 12 and 13 to a power supply and phase responsivecontrol apparatus 14. Clock thermostat 10 is similar to the clockthermostat disclosed in the Willis H. Gille US. Pat. No. 2,632,797 andhas a condition responsive element or bimetal for controlling a switch23 in response to the temperature of space 11. The position of bimetal20 and thus the control or set point of the thermostat can be adjustedin accordance with a time schedule by motor 21 which is connectedthrough a cam mechanism 22 to the support of bimetal 20. A clock 24 hashands which are controlled through a gear train 25 by motor 21 todisplay the time.

The control point of temperature responsive element 20 can be adjustedso that switch 23 closes at a predetermined temperature in space 11. Thecontrol point can be selectively adjusted at different values dependingupon the time of day or night by the homeowner selectively adjusting cammechanism 22. For example, the thermostats may be set to close switch 23when the temperature is at 72F. during the daytime and is at 65F. duringa selected nighttime period. Switch 23 is connected to the circuit ofwires 12 and 13 through a capacitor 26 and an adjustable resistor 27.

Apparatus 14 has a relay 30 for controlling a switch 31 adapted to beconnected in the energization circuit of environmental conditionchanging apparatus or a fuel controller or gas valve 32 furnishing fuelto furnace 33 which supplies conditioned medium or heated air to space11. A transformer 35 is connected to a conventional source to AC powerto supply a lower AC voltage from the secondary winding over a circuitcomprising diode or unidirectional current conducting device 42 andtransistor or semiconductor current control device 43 through circuits12 and 13 to continuously energize motor 21 of the clock thermostat.Diode 42 and transistor 43 are connected to conduct the current of theopposite half cycles to provide for full wave energization of motor 21.

A voltage divider circuit 44 connected across secondary 40 comprises aseries connection of a diode or unidirectional current conducting device45, a resistor 50, a resistor 51 and a resistor 52. Relay 30 and asilicon controlled rectifier (SCR) or semiconductor current controldevice 53 are connected in series with diode 45 to secondary 40, so thatupon the energization of SCR 53, relay 30 is energized to close switch31.

The voltage responsive means or control electrode 54 of rectifier 53 isconnected to a terminal 55 in between resistors 51 and 52 so that upon asimultaneous buildup of the voltage across rectifier 53 and acrossvoltage divider circuit 44 during each positive cycle of the AC source,should the voltage at terminal 55 reach the required firing voltage,rectifier 53 will fire to energize relay 30. The relay will remainenergized throughout the remaining half cycle and the next half cycle asa result of capacitor 60.

Connected to terminal 61, between resistors and 51 is a voltagebreakdown means or four-layer diode 62 which has a predetermined highresistance below a certain breakdown voltage at which voltage theresistance drops substantially to zero. Diode 62 is effective to shortout resistors 51 and 52 when the voltage at terminal 61 reaches thebreakdown voltage.

Transistor 43 is connected with a base terminal 63 to one side ofsecondary 40 a collector electrode 64 to terminal so that whentransistor 43 is conducting, resistor 52 is shorted out and controlledrectifier 53 cannot be energized.

OPERATION OF FIG. 1

With transformer 35 connected to the source of power, motor 21 in theclock thermostat is energized during both half cycles of AC voltage fromsecondary 40 through diode 42 during one half cycle and transistor 43during the other half cycle. Upon a call for heat by the thermostat,switch 23 is closed to connect capacitor 26 and resistor 27 in parallelwith motor 21 to change the load on circuit 12 and 13 and thus the phaserelationship or power factor of the voltage and current supplied tothermostat 10.

Normally, with only the inductive load of the clock motor connected tocircuits 12 and 13, the current lags the voltage so that even though theupper end of secondary 40 is positive to place a current downwardthrough the voltage divider circuit 44 at the beginning of such positivehalf cycle, the lagging or reverse current to the thermostat overcircuit 12 and 13 is flowing through transistor 43 to render thetransistor conductive to prevent energization of rectifier 53. Eventhough the voltage across the voltage divider 44 builds up gradually, asthe voltage of rectifier 53 is increased, the rectifier is notenergized. By the proper adjustment of the resistance in voltage dividercircuit 44, terminal 61 reaches a predetermined voltage level tobreakdown diode 62 before the lagging current to the load reverses todeenergize transistor 43. With only motor 21 connected in the circuit,rectifier 53 is not energized and gas is not supplied to the furnace.

Upon a call for heat by thermostat with the closure of switch 23, thepower factor and thus the phase relationship of the voltage and currentsupplied to thermostat 10 over circuit 12 and 13 changes. Assume thatthe phase relationship now is such that the current is in phase with thevoltage to have a zero power factor. When the power source provides apositive voltage at the upper end of transformer 40, and the current tothe thermostat is in phase or leading the voltage, the current no longeris flowing from base to emitter through transistor 45, but in theopposite direction through diode 42, hence the transistor isnon-conductive. As the voltage builds up on the positive half cyclethrough voltage divider 44, the voltage to the input of the controlledrectifier 53 reaches a level to fire rectifier 53 before the voltage atterminal 61 has reached the required level to break-down diode 62. Oncerectifier 53 becomes conductive, even though at a later time during thepositive cycle, diode 62 broke down, rectifier 53 remains conductive tomaintain relay 30 and thus valve 32 energized for the remaining portionof the positive cycle as well as the reverse cycle since capacitor 60maintains relay 30 energized. As long as the voltage and currentsupplied to thermostat 10 over circuits l2 and 13 is in phase or thecurrent leading the voltage, rectifier 53 is energized at the beginningof each positive cycle of the power source.

DESCRIPTION AND OPERATION OF FIG. 2

Referring to FIG. 2, another embodiment of the specific circuit of thepower supply and phase responsive apparatus of panel 14 shown in FIG. 1,is shown with the various elements which are common to the circuit ofFIG. 1, labeled with a number i (primed). A diode unidirectional currentconducting device 70 provides a separate circuit to connect relay 30'and rectifier 53 to the secondary 40 of the transformer of FIG. 1.

In addition a circuit is provided for maintaining relay 30' deenergizedshould thermostat 10 be removed to have an open circuit betweenconductors I2 and 13. The circuit has a resistor 69 and diode 71connected in series between wires 12 and 13 and a capacitor 72 connectedbetween a terminal intermediate resistor 69 and diode 71 and baseterminal 63' of transistor 43'.

The operation of the circuit of FIG. 2 is similar to that of the circuitof FIG. 1 in that upon a change in the power factor of the thermostat,current relay 30 is energized. With the additional circuit shown in FIG.2, if thermostat 10 is removed, for example, for repair, to cause thecircuit between wires 12 and 13 to be open, a bias current will continueto flow through transistor 43'. Capacitor 72 discharges through resistor69 during each positive cycle of the voltage of the power source tomaintain transistor conductive and prevent the silicon controlledrectifier 53' from firing thereby preventing energization of relay 30.

The embodiments of the invention in which an exclusive property or rightis claimed are defined as follows:

1. In power supply and phase responsive apparatus comprising,

an alternating current source of power, and

circuit means adapted to connect said source of power to a load, theload having a supply current and voltage and being adapted to change, tothereby affect the phase relationship of the voltage and currentsupplied to the load,

said circuit means comprising;

phase responsive means responsive to the phase relationship of thevoltage and current supplied to the load, and

first responsive means connected to said phase responsive means andresponsive to a change in said phase relationship of said voltage andcurrent, said phase responsive means comprises;

a voltage dividing circuit connected to said source of power,

output circuit means connecting said voltage dividing circuit to saidfirst responsive means to energize said first responsive means eachcycle when a first predetermined voltage level is reached upon saidvoltage of said source increasing from zero,

first circuit shorting means connected to said voltage dividing circuitmeans for shorting said output circuit means each cycle of said powersource when the voltage output of said voltage dividing circuit reachesa second predetermined value, and second circuit shorting meansconnected to said output circuit means for rendering said output circuitmeans ineffective as long as a lagging current is flowing to the loadwhereby said second circuit shorting means prevents said output meansfrom having an output of a first predetermined voltage level upon a risein voltage each cycle until said voltage rises to said secondpredetermined value and said first circuit shorting means is operated.

2. In the invention of claim 1 wherein said first responsive meanscomprises;

a silicon controlled rectifier connected to said source of power,

said output circuit means is connected to a control electrode of saidrectifier whereby said rectifier is rendered conductive throughout eachcycle when said output circuit has a first predetermined voltage level.

3. In the invention of claim 2 wherein said second shorting meanscomprises a semiconductor means connected in the load circuit, saidsemiconductor means shorting said output circuit when current is flowingin one direction to the load circuit, and

said first shorting means comprises a voltage breakdown means normallyhaving a high resistance but breaking down to a low resistance when asecond predetermined voltage is reached.

4. The invention of claim 3 comprising said further circuit meansconnected to said semiconductor shorting means to maintain said shortingmeans conductive when no currrent is flowing to the load until saidsecond predetermined voltage is reached,

said further circuit means including a capacitor which is charged tomaintain said semiconductor means conductive.

5. In power supply and phase responsive apparatus comprising;

an alternating current source of power, and

circuit means adapted to connect said source of power to a load, theload having a supply current and voltage and being adapted to change, tothereby affect the phase relationship of the voltage and currentsupplied to the load,

said circuit means comprising;

phase responsive means responsive to the phase relationship of thevoltage and current supplied to the load, and

first responsive means connected to said phase responsive means andresponsive to a change in said phase relationship of said voltage andcurrent,

said phase responsive means comprises;

a voltage dividing circuit connected to said source of power, saidcircuit comprising a unidirectional current conducting device and afirst and a second resistances connected in series to provide twooutputs, said first output having a higher voltage level than saidsecond,

circuit means connected to said second output for rendering said secondoutput ineffective when a predetermined phase exists between saidvoltage and current,

second circuit means connected to said first output for rendering saidfirst and second output ineffective when the voltage of said firstoutput reaches a first predetermined value,

said first responsive means comprises a current control means having acontrol electrode requiring a predetermined voltage level to render saidcontrol means conductive through one cycle of said source of power, and

third circuit means connecting said control electrode to said secondoutput for energizing said current control means each positive cycle ofAC voltage when the voltage from said second output reaches a secondpredetermined level before said output from said first output reachessaid first predetermined level.

6. The invention of claim 5 wherein separate circuit means are used toconnect said phase responsive means and said current control means tosaid source of power.

7. The invention of claim 5 comprising;

further circuit means connected to said circuit means to prevent saidsecond output from reaching said second predetermined level before saidoutput reaches said first predetermined level when no current flows tothe load.

8. In a phase responsive apparatus comprising;

voltage divider circuit means adapted to be connected across a source ofAC power, said voltage divider circuit means having a first and secondoutputs,

voltage responsive means connected to said first output of said voltagedivider circuit means to respond to a first predetermined voltage eachpositive cycle of said source of power,

first circuit means connected to said output for rendering said firstoutput of said voltage divider means ineffective for a remainder of eachcycle when the voltage level of said second output of said voltagedivider circuit means reaches a predetermined level higher than saidfirst predetermined level of each positive cycle, and

circuit means responsive to a predetermined reverse current flow to aload during a positive voltage cycle connected for rendering said firstpredetermined voltage ineffective for a portion of said cycle until saidfirst circuit means is effective.

1. In power supply and phase responsive apparatus comprising, analternating current source of power, and circuit means adapted toconnect said source of power to a load, the load having a supply currentand voltage and being adapted to change, to thereby affect the phaserelationship of the voltage and current supplied to the load, saidcircuit means comprising; phase responsive means responsive to the phaserelationship of the voltage and current supplied to the load, and firstresponsive means connected to said phase responsive means and responsiveto a change in said phase relationship of said voltage and current, saidphase responsive means comprises; a voltage dividing circuit connectedto said source of power, output circuit means connecting said voltagedividing circuit to said first responsive means to energize said firstresponsive means each cycle when a first predetermined voltage level isreached upon said voltage of said source increasing from zero, firstcircuit shorting means connected to said voltage dividing circuit meansfor shorting said output circuit means each cycle of said power sourcewhen the voltage output of said voltage dividing circuit reaches asecond predetermined value, and second circuit shorting means connectedto said output circuit means for rendering said output circuit meansineffective as long as a lagging current is flowing to the load wherebysaid second circuit shorting means prevents said output means fromhaving an output of a first predetermined voltage level upon a rise involtage each cycle until said voltage rises to said second predeterminedvalue and said first circuit shorting means is operated.
 2. In theinvention of claim 1 wherein said first responsive means comprises; asilicon controlled rectifier connected to said source of power, saidoutput circuit means is connected to a control electrode of saidrectifier whereby said rectifier is rendered conductive throughout eachcycle when said output circuit has a first predetermined voltage level.3. In the invention of claim 2 wherein said second shorting meanscomprises a semiconductor means connected in the load circuit, saidsemiconductor means shorting said output circuit when current is flowingin one direction to the load circuit, and said first shorting meanscomprises a voltage breakdown means normally having a high resistancebut breaking down to a low resistance when a second predeterminedvoltage is reached.
 4. The invention of claim 3 comprising said furthercircuit means connected to said semiconductor shorting means to maintainsaid shorting means conductive when no currrent is flowing to the loaduntil said second predetermined voltage is reached, said further circuitmeans including a capacitor which is charged to maintain saidsemiconductor means conductive.
 5. In power supply and phase responsiveapparatus comprising; an alternating current source of power, andcircuit means adapted to connect said source of power to a load, theload having a supply current and voltage and being adapted to change, tothereby affect the phase relationship of the voltage and currentsupplied to the load, said circuit means comprising; phase responsivemeans responsive to the phase relationship of the voltage and currentsupplied to the load, and first responsive means connected to said phaseresponsive means and responsive to a change in said phase relationshipof said voltage and current, said phase responsive means comprises; avoltage dividing circuit connected to said source of power, said circuitcomprising a unidirectional current conducting device aNd a first and asecond resistances connected in series to provide two outputs, saidfirst output having a higher voltage level than said second, circuitmeans connected to said second output for rendering said second outputineffective when a predetermined phase exists between said voltage andcurrent, second circuit means connected to said first output forrendering said first and second output ineffective when the voltage ofsaid first output reaches a first predetermined value, said firstresponsive means comprises a current control means having a controlelectrode requiring a predetermined voltage level to render said controlmeans conductive through one cycle of said source of power, and thirdcircuit means connecting said control electrode to said second outputfor energizing said current control means each positive cycle of ACvoltage when the voltage from said second output reaches a secondpredetermined level before said output from said first output reachessaid first predetermined level.
 6. The invention of claim 5 whereinseparate circuit means are used to connect said phase responsive meansand said current control means to said source of power.
 7. The inventionof claim 5 comprising; further circuit means connected to said circuitmeans to prevent said second output from reaching said secondpredetermined level before said output reaches said first predeterminedlevel when no current flows to the load.
 8. In a phase responsiveapparatus comprising; voltage divider circuit means adapted to beconnected across a source of AC power, said voltage divider circuitmeans having a first and second outputs, voltage responsive meansconnected to said first output of said voltage divider circuit means torespond to a first predetermined voltage each positive cycle of saidsource of power, first circuit means connected to said output forrendering said first output of said voltage divider means ineffectivefor a remainder of each cycle when the voltage level of said secondoutput of said voltage divider circuit means reaches a predeterminedlevel higher than said first predetermined level of each positive cycle,and circuit means responsive to a predetermined reverse current flow toa load during a positive voltage cycle connected for rendering saidfirst predetermined voltage ineffective for a portion of said cycleuntil said first circuit means is effective.